Centered on the theories of Carol Dweck (2006) and James Burns (1978), an expanding theory case study approach was used to analyze how growth mindset and transformational leadership influence instructional decisions made specifically for economically disadvantaged students. In addition, analysis of how leaders perceive these decisions to have influenced student achievement based on the application of diversity, equity, and inclusion (DEI) strategies was explored. This study included five district leaders and four building leaders from one K-6 and four K-12 New York State suburban school districts, where at least 40 percent of students enrolled live in low-income or economically disadvantaged households, also known as Title one. District leaders were interviewed, followed by a focus group including both district and building leaders. Several themes emerged as a result of data analysis, supporting the findings that the synthesis of a growth mindset, transformational leadership qualities, and a commitment to DEI strategies, empower educational leaders to drive positive change and significantly influence student achievement outcomes. Implications suggest further research is needed to determine how to ultimately remove barriers that still exist for marginalized student populations to create equitable outcomes for all students to achieve success. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]